Downside of sealed cabinets?

madfloyd said:
My SC's and IC's between the phono preamp and preamp are MIT. I have a 25ft run of Transparent (single ended unfortunately) between my preamp and amps (left over from my Doshi setup) which I haven't replaced. Unfortunately my phono cable is non-removable and I have no idea what quality it is (Triplanar arm).

Caelin Gabriel of Shunyata did mention to me that he was slightly worried that I have might have some restriction of current (forget the term Shunyata uses for this) because I have some Equi-tech transformers between my main electrical box and the amp outlets - where the transformer *could* be too small. He suggested having an electrician bypass the transformer as an experiment. Perhaps that might be worth doing.
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I seriously doubt your Equi-tech Balanced transformers are limiting power, infact it's just the reverse, they provide more power then the circuit can provide alone during peek times because the transformers act as a large capacitor which provides you that extra current when you need it. If you bypass your balanched transformers you will defeat the purpose. I have 1 Balanced Power Technologies transformer on a dedicated 20amp circut which powers my 2 Pass Labs xa160.5 amps. I never have issue with insufficient power even at very high volume levels.

The Balanced Power Technologies transformer provides 20A RMS and 60A peak power and that's more peek power then you can get from a 20amp circuit alone.
 
madfloyd said:
I'd like to know if what I think I'm experiencing (i.e. what I'm perceiving) is a known drawback of sealed cabinet speakers.

I've noticed with my Magico S5's that when I raise the volume past a certain threshold the tonal balance changes - the bass stops getting louder - it sort of 'compresses' - and the result is that it sounds too lean (e.g. highs too pronounced, bass too weak).

Is this normal for sealed cabinets?

I should point out that the volume threshold I'm referring to is about 88-90db (lest somebody think I'm playing at much higher levels than that).

As a result, I won't play these speakers loud because it doesn't sound great. Clean, but the imbalance destroys my enjoyment.

Comments?
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Just throwing something out here, does a sealed cabinet operate more efficiently in a small closed off room vs a wide open room ? Maybe the problem is the room
 
CPP said:
Just throwing something out here, does a sealed cabinet operate more efficiently in a small closed off room vs a wide open room ? Maybe the problem is the room
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Both sealed and ported speakers work that way.

If you can, play with the listening position as well as the speaker positioning.
 
Face said:
Both sealed and ported speakers work that way.

If you can, play with the listening position as well as the speaker positioning.
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I guess I was trying to understand is the relationship a sealed speaker had on the reproduction of bass within a sized room..... Would a ported speaker cabinet provide better bass that a sealed speaker cabinet ?

I know my 59 Fender Bassman which is open in the back produces those lower bass freq a lot better than say my sealed Vox bass amp. Same could be said about audio speaker cabinets.
 
Audioseduction said:
I seriously doubt your Equi-tech Balanced transformers are limiting power, infact it's just the reverse, they provide more power then the circuit can provide alone during peek times because the transformers act as a large capacitor which provides you that extra current when you need it. If you bypass your balanched transformers you will defeat the purpose. I have 1 Balanced Power Technologies transformer on a dedicated 20amp circut which powers my 2 Pass Labs xa160.5 amps. I never have issue with insufficient power even at very high volume levels.

The Balanced Power Technologies transformer provides 20A RMS and 60A peak power and that's more peek power then you can get from a 20amp circuit alone.
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George,

The reason I am worried about the Equi=tech transformer is this comment (which is not from Shunyata but a friend):

"I think for most systems the 2 KVA transformer size may be on the low side. I'm thinking you would be happier with a larger 3 KVA or 5 KVA transformer, if you plan on using larger solid state amplifiers."

Shunyata said:

"What is the capacity of the Eq transformers in maximum current or VA? I use an isolation transformer for our reference room also. However, it has a capacity of 200 amps and is larger than the transformer that feeds the building power. Trnasformers, unless they have a very large reserve capacity will restrict DTCD and compress dynamics in an audio system. If you can do an experiment it would be enlightening. See if you can bypass the transformers to the circuit that feeds the amplifiers and see what happens."
 
CPP said:
I guess I was trying to understand is the relationship a sealed speaker had on the reproduction of bass within a sized room..... Would a ported speaker cabinet provide better bass that a sealed speaker cabinet ?

I know my 59 Fender Bassman which is open in the back produces those lower bass freq a lot better than say my sealed Vox bass amp. Same could be said about audio speaker cabinets.
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Sealed speaker's roll off generally matches room gain better, providing flat bass response instead of a large peak. I can post some examples later tonight.
 
madfloyd said:
George,

The reason I am worried about the Equi=tech transformer is this comment (which is not from Shunyata but a friend):

"I think for most systems the 2 KVA transformer size may be on the low side. I'm thinking you would be happier with a larger 3 KVA or 5 KVA transformer, if you plan on using larger solid state amplifiers."

Shunyata said:

"What is the capacity of the Eq transformers in maximum current or VA? I use an isolation transformer for our reference room also. However, it has a capacity of 200 amps and is larger than the transformer that feeds the building power. Trnasformers, unless they have a very large reserve capacity will restrict DTCD and compress dynamics in an audio system. If you can do an experiment it would be enlightening. See if you can bypass the transformers to the circuit that feeds the amplifiers and see what happens."
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The BPT unit is 2.2 KVA with peeks to 6.6 KVA.
 
at the spls you listen at - assuming its at the listening position -- the pass amps should be more than adequate. this is pure speculation but your S5 may be experiencing a suck out at certain bass freq, that, or the Wilson's were bloated to begin with and an adjustment period is in order. sealed systems are less efficient in general and will compress at high spl sooner than a ported system, the irregular bass response is more likely the result of other factors like your room (eliminating the amp/cables from the equation).
 
Here is a high end 15" woofer in a sealed enclosure with gain modeled to my room. See the relatively smooth and flat bass response.

Ja7Qz5I.gif


Now here's the same woofer in the same enclosure, but ported. The bottom end becomes more efficient, but not in a linear fashion. There is a rise from 25-70hz, but less bass below 25hz.

ORNrvvq.gif


Now let's look at this with a smaller woofer.

HjyBgoc.gif


IMO, the differences, or problems are more severe.

NCAfzwC.gif
 
Face said:
Here is a high end 15" woofer in a sealed enclosure with gain modeled to my room. See the relatively smooth and flat bass response.

Ja7Qz5I.gif


Now here's the same woofer in the same enclosure, but ported. The bottom end becomes more efficient, but not in a linear fashion. There is a rise from 25-70hz, but less bass below 25hz.

ORNrvvq.gif


Now let's look at this with a smaller woofer.

HjyBgoc.gif


IMO, the differences, or problems are more severe.

NCAfzwC.gif
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You use the same drivers for ported and sealed design? As I understood it, one of the issues with sealed enclosures is the heat buildup in the driver.
 
puroagave said:
at the spls you listen at - assuming its at the listening position -- the pass amps should be more than adequate. this is pure speculation but your S5 may be experiencing a suck out at certain bass freq, that, or the Wilson's were bloated to begin with and an adjustment period is in order. sealed systems are less efficient in general and will compress at high spl sooner than a ported system, the irregular bass response is more likely the result of other factors like your room (eliminating the amp/cables from the equation).
Click to expand...

I don't think you're going to experience that compression with the Magicos, certainly not until much, much louder volumes.
 
Thank you Face, these are very helpful. In regards to the amps/speakers situation, with all due respect to Pass, bass has never been their high point (typical to class A). Madfloyd should try a different amp, just so he can see what can be achieved, bass wise, on these speakers. Unlike the Wilson, that are so blotted in the bass, the Magico do need a linear amp to show their strength. Room poisoning can help, but I don’t think the Pass 160 is ideal for these speakers, IF, you want to play loud and hard. Before I get slammed, make sure you actually tried it. Even a cheap class D amplifier will expose the weakness in the Pass bass. Should not be too hard to try.
 
LVB said:
Thank you Face, these are very helpful. In regards to the amps/speakers situation, with all due respect to Pass, bass has never been their high point (typical to class A). Madfloyd should try a different amp, just so he can see what can be achieved, bass wise, on these speakers. Unlike the Wilson, that are so blotted in the bass, the Magico do need a linear amp to show their strength. Room poisoning can help, but I don’t think the Pass 160 is ideal for these speakers, IF, you want to play loud and hard. Before I get slammed, make sure you actually tried it. Even a cheap class D amplifier will expose the weakness in the Pass bass. Should not be too hard to try.
Click to expand...

Hmm, I do have some Spectron monos in my home theater...
 
LVB said:
Thank you Face, these are very helpful. In regards to the amps/speakers situation, with all due respect to Pass, bass has never been their high point (typical to class A). Madfloyd should try a different amp, just so he can see what can be achieved, bass wise, on these speakers. Unlike the Wilson, that are so blotted in the bass, the Magico do need a linear amp to show their strength. Room poisoning can help, but I don’t think the Pass 160 is ideal for these speakers, IF, you want to play loud and hard. Before I get slammed, make sure you actually tried it. Even a cheap class D amplifier will expose the weakness in the Pass bass. Should not be too hard to try.
Click to expand...

In regards to excellent bass, one of the strength of the Martin Logan Summit Xs active bass section having 400W of ICEPower Class D to drive a pair of 10” woofers in each speaker cabinet while the xa160.5s powers the panels. So I'm driving a total of 720W per speaker.
 
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